Status of the coral reefs and adjacent environments of the U.S. Virgin Islands

The U.S. Coral Reef task force calls for local action strategies to reduce key threats to U.S. coral reef ecosystems. The USVI locally driven initiative was designed to identify and implement priority actions to reduce key threats to coral reefs through partnerships and collaborative actions among federal, state, territorial, and non-governmental partners. The U.S. Virgin Islands directed all LAS activities towards the newly formed St. Croix East End Marine Park (STXEEMP). The LAS focused on four areas: (1) Lack of awareness (Goal - Build awareness of the importance of coral reefs and teach and encourage positive behaviors that will protect and nurture them; (2)  Recreational use (Goal – Reduce impacts of recreational use to coral reef systems within the STXEEMP); (3) Fishing (Goal - To provide resource managers with sufficient baseline information to assess the current status of coral reef ecosystems within the STXEEMP, to assess existing harvest patterns of fisheries resources from the STXEEMP, and to determine the relative impact of fishing within the STXEEMP; and (4) Land Based Sources of pollution (Goal - Reduce non-point source pollutants in watersheds contributing to the East End Marine Park).

The St. Croix East End Marine park (STXEEMP)

Results from water quality monitoring programs in the USVI show that water quality, while generally good, continues to decline, in large measure due to point and nonpoint sources of pollution. According to the 2008 State of the Coral Reef Ecosystems of the U.S. Virgin Islands report (Rothenberger, 2008), surface waters in the USVI continue to be adversely affected by increasing sources of pollutants, ranging from runoff from construction sites and unpaved roads, failure of best management practices on construction sites, failure of onsite disposal systems, failing sewage systems and the direct discharge of waste overboard from vessels. The major problems affecting nearshore waters are sedimentation and bacterial contamination. Regulation of such activities is difficult and largely voluntary. Sewage bypasses from the municipal sewage system and wastewater effluent from both permitted and illegal discharges continue as well. Efforts are underway to remedy these problems or mitigate their effects.

The USVI did not escape from the effects of the Caribbean mass bleaching event of 2005.

In some areas, more than 90 percent of the coral cover bleached during the 2005 bleaching event.  In addition to mortality associ­ated with bleaching, bleached corals also suffered significant losses due to disease. The overwhelming mortality documented was attributed to white plague disease, caused by the bacterial pathogen, Auratimonas coralicida. White plague disease  is characterized by an abrupt line or band of white, exposed coral skeleton that separates living tissue from algal-colonized skeleton, and often a narrow band of bleached tissue may be visible adjacent to exposed skeleton. Usually beginning at the base of a colony, it spreads quickly upward and outward.

Coral recovery from the bleaching was variable. Some corals showed significant recovery followed by disease impacts, while others appeared to die as a result of the bleaching event itself.

Smooth brain coral, Diploria strigosa with white plague that is spreading upwards from the colony base. (Photo: Dr Andrew bruckner/NOAA)

The overall consensus of experts is that coral reef ecosystems in the USVI are in decline and continue to be threatened by a number of natural and anthropogenic stressors. The long-term impacts of significant loss of live coral cover may not be known for years or decades. Changes to coral reef architecture may have significant effects on the populations of fishes and invertebrates which depend upon the corals. Baseline information is needed on coral diseases and coral resiliency. Much more research is needed to understand the synergistic (cumulative) effects of stressors. Inadequate information is available on reef fisheries for commercially and recreationally important fishes and invertebrates, such as the mutton snapper, some groupers, and queen conch.

Scientists recommend that management and enforcement capacity of regulations be heightened.  These include increased collaboration between federal and territorial agencies working on coral reef issues in the USVI, improving enforce­ment of existing regulations, expanding management capacity, and increasing awareness of coral reef ecosystems among residents and visitors. Progress has been made in many of these areas, but additional efforts are warranted.

Thousands of Americans participate yearly in snorkeling and scuba-diving activities in the Caribbean, with many tourists traveling to the U.S. Virgin Islands. However, as coral reef quality and habitat declines, tourists may go elsewhere, with a resulting loss of millions of dollars to the USVI economy.

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